Inhibition and removal characteristics of trichloroethylene on anaerobic hydrolysis acidifying bacteria

Trichloroethylene (TCE) is a typical organic pollutant in petrochemical wastewater, which is highly toxic to microorganisms. Batch bioassays of volatile fatty acid were carried out to explore the inhibitory effect of TCE on acid production of anaerobic hydrolysis acidifying bacteria, the variation of extracellular polymeric substances (EPS) and mud zeta potential of hydrolysis acidifying bacteria under TCE shock, and the removal characteristics of TCE. The results showed that TCE at a concentration of 75 mg/L (semi-inhibitory concentration, EC₅₀) had an inhibitory effect on the acid production of hydrolysis acidifying bacteria. With the increase of TCE concentration, the protein concentration in EPS of hydrolsis acidifying bacteria first increased and then decreased. The maximum value of protein concentration in EPS was (33.94±0.25)mg/L when TCE concentration was 50 mg/L. The results of zeta potential showed that the coagulation performance of sludge increased with the increase of TCE concentration (0-100 mg/L). The dechlorination ability of anaerobic hydrolysis acidifying bacteria to TCE decreased with the increase of TCE concentration, and the dechlorination rate of TCE converted by hydrolysis acidifying bacteria was 77.83% when the concentration of TCE was 10 mg/L. It decreased to 6.67% at 200 mg/L. TCE had a strong inhibitory effect on hydrolysis acidifying bacteria. TCE mainly inhibited microbial activity by inhibiting the protein synthesis of cells, thereby limiting the ability of hydrolysis acidifying bacteria to degrade TCE.